<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>

        .box1{
            width: 200px;
            height: 200px;
            background-color: tomato;

            /*display: block;*/

            /*visibility: hidden;*/

            /*opacity: 0;*/

        }

    </style>
</head>
<body>

<div class="box1"></div>

</body>
</html>